A predatory bug that feeds readily on thrips. Unlike many other thrips predators, Orius are able to feed on adults as well as immatures. They can survive on alternate prey such as aphids and moth eggs when thrips numbers are low. Pollen is an important component of the diet of Orius so it is useful for them to have access to a source of flowers in the nearby vicinity.
Belonging to the group of insects known as the ‘sucking bugs’, Orius are characterised by having powerful hypodermic-like mouthparts that they use to impale their prey. Once captured, their victims are consumed by sucking the body contents directly through this structure.
Orius pass from the egg through several larval stages before developing wings and becoming an adult. Adults are mobile and able to move readily through the crop seeking out thrips as they do so. Both immature stages and adults are able to feed on thrips but the adults are most aggressive. Female Orius lay their eggs into plant tissue. The life cycles takes from 2-4 weeks depending on temperature.
- Thrips (including western flower thrips)
- Also feed on aphids, whitefly and moth eggs
Because Orius need supplemental pollen as part of their dietary intake they are best applied in crops where pollen is naturally abundant (eg capsicum, eggplant, strawberry, raspberry and gerbera). Creating a habitat with high plant diversity (which includes flowering species) can greatly improve the survival and population development of Orius tantillus.
Orius should be released at or before the first sign of thrips activity as long as there is pollen present to support them. Use of yellow and blue sticky traps can help to identify thrips activity. Thripher pheromone septae are recommended to improve trap capture and quality of monitoring data.
Orius are supplied in cardboard tubes containing at least 1,000 adult predatory bugs. They are mixed with buckwheat hulls to improve distribution. A supply of moth eggs is included as a food source. A segment of green bean is also contained within the tube to offer additional moisture to the Orius on their journey to you. The bean may also contain freshly laid Orius eggs so it should be placed within the crop at the time of release. Roll the tube gently to distribute the predators uniformly in the medium and sprinkle the contents gently onto the leaves of the host crop. It is best if the medium remains in the upper parts of the crop. However adult Orius are capable of flight if some happen to drop to the greenhouse floor or surrounding soil. Avoid extremes of temperature and humidity during the critical period of release.
Recommended release rates
Situation Orius/m2 Number of releases Preventative 2 – 3 2 – 3 Curative 3 – 10 1 – 3
A note on release rates: Unlike chemicals which generally exhibit a clearly defined dose response curve, with beneficial insects, more is always better. However, they are costly to produce and the goal should be to achieve the best results at minimal cost. We are constantly trying to strike a balance between cost and efficacy. There are many factors that should be considered including the value of the crop, the magnitude of the pest population and the activity (or otherwise) of naturally occurring beneficial species. Also unlike chemicals, where it is common to respond to pest populations that have already exceeded some ‘economic threshold’, we recommend establishing beneficials early in the life of the crop before pest populations reach threatening levels. In most cases our releases are inoculative and we anticipate that our beneficials will establish and breed up within the crop to give long term control. As a general principle, 2-3 releases of modest numbers is better than a single large release – this reduces risk, improves establishment and accelerates the development of multiple overlapping generations of the beneficial species.
Continued survival and efficacy of Orius predatory bugs in any crop will depend on availability of food (both prey and pollen) as well as environmental conditions (temperature, humidity, dust and especially chemical residues). Orius are very effective predators but are sensitive to many pesticides. Take great care with pesticide selection and application in crops where they are deployed.
Cultural practices to aid establishment
Availability of pollen and prey plus proximity of plant biodiversity are all tools to aid establishment and ensure continued survival of Orius predatory bugs.
Many commonly used pesticides are harmful to Orius. One or two closely related species have been used for several years in Europe as very effective tools for thrips managment. We suggest you consult the Biobest Side Effects Manual for an indication of potential harmful effect on Orius bugs before applying any pesticides.
Orius are despatched by express post or overnight courier and should be received within 48 hours. They should be released as soon as practicable after arrival – preferably during the cooler hours of morning or dusk. If necessary they can be stored for one or two days in a cool, dark place (10-15°C is ideal).